This is a very slim chance, but you can try right clicking on the folder that it was stored in and select properties. Go to the previous versions tab and see if it was saved in there. If not you can try using GetDataBack for NTFS to see if it's recoverable (you'll want to use your main drive as an external) and run the program on a different computer.

If you went through options 2 or 3, you should (each time you boot) see a boot manager of some kind (like at the bottom of link 2) displaying a list of all the operating systems on your machine. Do you see this?

> I have Ubuntu in windows 7, which is accidentally deleted.
What exactly did you delete?
There is a big difference between deleting a file, and deleting an operating system.

If you managed to delete one (or other) of the operating systems, by say choosing "use whole disk" when you chose to install Ubuntu, then all your windows stuff is truly gone. You either need your windows installation CD, or a recovery partition

I guess you have access to another machine (which is where you posted from). The important thing is to do NOTHING without fully understanding what you're about to do. If there is anything to save, then trying random things could make things worse.